1. Field of the Invention
The invention relates to disc support structures and means of producing the same and somewhat more particularly to Si or SiC support structures for supporting semiconductor crystal discs during processing thereof and a method of producing such structures.
2. Prior Art
Support structures composed of Si or SiC are required in semiconductor techniques to maintain crystal discs composed of a semiconductor material, such as silicon, in a position during a dopant diffusion or an annealing process of the discs. In the prior art, such support structures have been produced from solid silicon bodies, which is quite difficult and very expensive.
Methods of producing tubes or hollow bodies composed of semiconductor material by thermally induced gas deposition process are known. For example, German Offenlegungsschrift No. 2,125,085.1 (corresponding to U.S. Pat. No. 3,747,559), which is assigned to the instant assignee, discloses a process wherein a closed-end tube composed of silicon is produced by a thermally induced gas deposition process. In accordance with this process, a gas mixture of hydrogen and silico-chloroform is fed into a reaction chamber having a graphite carrier member therein which is heated up to the decomposition temperature of the silicon compound (about 1200.degree. C.) so that the silicon compound decomposes and a deposit of silicon is formed about the carrier member. Upon removal of the carrier member without destruction of the deposit, a tube is attained. Such tubes have been used for supporting crystal discs during diffusion and/or annealing processes in accordance with semiconductor techniques.